Aico Carbon Monoxide Detectors
This official sponsor may provide discounts for members


  1. S

    Hole in joist - question on span

    I need to make a hole in a floor joist - I know it needs to be within 0.25 to 0.4 x the span, and in the middle of the joist etc, but I can't find a clear answer on what the span is when there is a supporting wall in the middle. Is the span seen to be between the outer wall, and the supporting...
  2. Pat H

    Drilling joists

    Doing a loft conversion and wondering about joist drilling. OSG states to drill in the middle of the joist 0.25 to 0.4 of joist length. I have 6" joists but the bottom 4" will be filled with 100mm celotex so If I drill at half way my cabling will be in the way of the insulation. It makes more...
  3. L

    Notching the side of a joist?

    I know the regs for the regular notching of joists, but I can find nothing about notching up the side of a joist. I need to route my cables up past a large wooden beam 4500mm x 400mm, 115mm thick. Do the normal rules apply? 0.07-0.25 of the length and 0.125 of the depth? Or is it a no go? Cheers
  4. B

    Cable in narrow space - how to fix it?

    10mm 2+e must run in a 30mm wide gap under floor between wall and joist. Must also be >50mm from surface or enclosed in earthed metal or impenetrable armour. The distance is only 1m. It is not possible to reach 50mm down the gap to fix nail/screw in cable clips. Would any of the following...
  5. N

    Kneeling Board For Attic?

    Im wondering if any body has used a kneeling board in attics. The kit I'm looking for was A kind of folding contraption like a mug holder for the wall. You could turn it into a kneeling board or push it narrow and it would become a walkway. First seen them maybe 8 years ago. Googles failed me...
  6. 1Justin

    Posi-joist installation & cable support.

    I have a customer costing up a new build using steel herringbone composite timber/steel type "Posi-joists" for first floor and flat roof areas. I called up the joist manufacturer and was amazed to hear that no-one had EVER asked them about installing electrics between, and support thereof. He...
  7. driverman

    domestic new build first fixing

    Hi Guys, I'm going to wire a completely new build house soon and I've been out of game for many years.The house has those Z joist which have timber top and bottom and hollow between, using metal Z frames for strength. My question is for those of you that come across this a lot is, When...
  8. N

    general building regulation

    Sorry guys just looking for a little help here, I done a homer for a joiner and I cut a notch out a load baring exterior wall and fitted a metal back box, the client is complaining and is trying to charge me, but I know that I'm aloud to notch up to 25% of the width of the stud and basically I'm...
  9. O

    running mains cable underfloor along a concrete sub floor

    I have just had an extension built to extend the kitchen and provide another room.The old kitchen area has honeycomb walls supporting a floor joists on a concrete base. The base is clean and without debris. The builder has suggested that when the electrician comes to to wire it up he could pass...
  10. P

    floor boards

    Hi Guys, Just wondering what method you use for getting up floorboards without causing too much damage ? :smartass:
  11. Paul.M

    It's the Plasterers Fault This Time!

    Over the past 2 weeks I've had a plumber drilling into a 4mm rmf, Tuesday a home owner putting a picture nail into a 2.5mm rmf and this evening a plasterer putting a 4 inch fixing screw into a sw feed/sw live! Whoops :):):). He tried to cover it up but was found out when the elderly couple...
  12. S

    Requirements for drilling holes in joists

    Could anyone point me in the right direction for requirements to drilling joists? eg. distance out from end of etc... Have used a guidance sheet before but really dont have the time to trawl google searching for regs. Cheers
  13. R

    Drilling joists Take a look at above PDF what do they mean by the depth of the joist, the diagram seems to indicate the thickness ??
  14. S

    good joist drill?

    Can anyone recommend a good joist driller? Purchased many drills in my time & still I am unsure to what joist drills to supply my lads with. Tried the angle makita's & they were useless. any ideas???????:(
Top Bottom